The present invention relates to an electrical circuit and particularly to a touch controlled electrical switching circuit.
There exists a variety of electrical switching circuits which respond to a person's touch on a touch pad which can be in the form of a lamp base or a specific surface area of an electrical appliance to be actuated. Such circuits represent a convenient manner by which a consumer can easily operate appliances without the need for manually actuating a conventional toggle, push-button or other type switch. Touch controlled electrical switching circuits have become increasingly popular; for example, in use in controlling table lamps, floor lamps and the like although they have other applications as well. U.S. Pat. Nos. 4,119,864 and 4,360,737 are representative of existing touch controlled switch circuits. Typically, such circuits employ the human body as an antenna for picking up 60 Hz radiation existing in an environment by virtue of the line frequency power in the building and utilizes the induced voltage as a trigger signal for controlling the touch controlled electrical circuit. Such systems, however, can suffer from erratic operation due to variations in the nature of the ambient 60 Hz field and the physiological makeup of the person utilizing the system. Also the prior art systems typically utilize a pulse control for controlling a solid-state switch such as a Triac to be conductive only during a portion of each cycle of operation of the AC power supply thereby reducing the efficiency of such systems.